

<!DOCTYPE html>
<html lang="zh-CN" data-default-color-scheme=auto>



<head>
  <meta charset="UTF-8">
  <link rel="apple-touch-icon" sizes="76x76" href="/img/avatar.gif">
  <link rel="icon" href="/img/avatar.gif">
  <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=5.0, shrink-to-fit=no">
  <meta http-equiv="x-ua-compatible" content="ie=edge">
  
  <meta name="theme-color" content="#2f4154">
  <meta name="author" content="马振东">
  <meta name="keywords" content="Java,计算机,数据结构">
  
    <meta name="description" content="问题描述假设要在足够多的会场里安排一批活动，并希望使用尽可能少的会场。设计一个有效的贪心算法进行安排。 对于给定的k个待安排的活动，计算使用最少会场的时间表。">
<meta property="og:type" content="article">
<meta property="og:title" content="会场安排问题-贪心算法">
<meta property="og:url" content="https://bolg.plumdong.top/2019/10/30/%E4%BC%9A%E5%9C%BA%E5%AE%89%E6%8E%92%E9%97%AE%E9%A2%98-%E8%B4%AA%E5%BF%83%E7%AE%97%E6%B3%95/index.html">
<meta property="og:site_name" content="PlumDong Bolg">
<meta property="og:description" content="问题描述假设要在足够多的会场里安排一批活动，并希望使用尽可能少的会场。设计一个有效的贪心算法进行安排。 对于给定的k个待安排的活动，计算使用最少会场的时间表。">
<meta property="og:locale" content="zh_CN">
<meta property="article:published_time" content="2019-10-30T09:25:04.000Z">
<meta property="article:modified_time" content="2023-03-13T06:57:46.556Z">
<meta property="article:author" content="马振东">
<meta property="article:tag" content="C++">
<meta property="article:tag" content="算法不能丢">
<meta property="article:tag" content="Java">
<meta name="twitter:card" content="summary_large_image">
  
  
  
  <title>会场安排问题-贪心算法 - PlumDong Bolg</title>

  <link  rel="stylesheet" href="https://lib.baomitu.com/twitter-bootstrap/4.6.1/css/bootstrap.min.css" />



  <link  rel="stylesheet" href="https://lib.baomitu.com/github-markdown-css/4.0.0/github-markdown.min.css" />

  <link  rel="stylesheet" href="https://lib.baomitu.com/hint.css/2.7.0/hint.min.css" />

  <link  rel="stylesheet" href="https://lib.baomitu.com/fancybox/3.5.7/jquery.fancybox.min.css" />



<!-- 主题依赖的图标库，不要自行修改 -->
<!-- Do not modify the link that theme dependent icons -->

<link rel="stylesheet" href="//at.alicdn.com/t/font_1749284_hj8rtnfg7um.css">



<link rel="stylesheet" href="//at.alicdn.com/t/font_1736178_lbnruvf0jn.css">


<link  rel="stylesheet" href="/css/main.css" />


  <link id="highlight-css" rel="stylesheet" href="/css/highlight.css" />
  
    <link id="highlight-css-dark" rel="stylesheet" href="/css/highlight-dark.css" />
  




  <script id="fluid-configs">
    var Fluid = window.Fluid || {};
    Fluid.ctx = Object.assign({}, Fluid.ctx)
    var CONFIG = {"hostname":"bolg.plumdong.top","root":"/","version":"1.9.4","typing":{"enable":true,"typeSpeed":70,"cursorChar":"_","loop":false,"scope":[]},"anchorjs":{"enable":true,"element":"h1,h2,h3,h4,h5,h6","placement":"left","visible":"hover","icon":""},"progressbar":{"enable":true,"height_px":3,"color":"#29d","options":{"showSpinner":false,"trickleSpeed":100}},"code_language":{"enable":true,"default":"TEXT"},"copy_btn":true,"image_caption":{"enable":true},"image_zoom":{"enable":true,"img_url_replace":["",""]},"toc":{"enable":true,"placement":"right","headingSelector":"h1,h2,h3,h4,h5,h6","collapseDepth":0},"lazyload":{"enable":true,"loading_img":"/img/loading.gif","onlypost":false,"offset_factor":2},"web_analytics":{"enable":false,"follow_dnt":true,"baidu":null,"google":null,"gtag":null,"tencent":{"sid":null,"cid":null},"woyaola":null,"cnzz":null,"leancloud":{"app_id":null,"app_key":null,"server_url":null,"path":"window.location.pathname","ignore_local":false}},"search_path":"/local-search.xml"};

    if (CONFIG.web_analytics.follow_dnt) {
      var dntVal = navigator.doNotTrack || window.doNotTrack || navigator.msDoNotTrack;
      Fluid.ctx.dnt = dntVal && (dntVal.startsWith('1') || dntVal.startsWith('yes') || dntVal.startsWith('on'));
    }
  </script>
  <script  src="/js/utils.js" ></script>
  <script  src="/js/color-schema.js" ></script>
  


  
<meta name="generator" content="Hexo 5.4.0"><link rel="alternate" href="/atom.xml" title="PlumDong Bolg" type="application/atom+xml">
</head>


<body>
  

  <header>
    

<div class="header-inner" style="height: 60vh;">
  <nav id="navbar" class="navbar fixed-top  navbar-expand-lg navbar-dark scrolling-navbar">
  <div class="container">
    <a class="navbar-brand" href="/">
      <strong>PlumDong Bolg</strong>
    </a>

    <button id="navbar-toggler-btn" class="navbar-toggler" type="button" data-toggle="collapse"
            data-target="#navbarSupportedContent"
            aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
      <div class="animated-icon"><span></span><span></span><span></span></div>
    </button>

    <!-- Collapsible content -->
    <div class="collapse navbar-collapse" id="navbarSupportedContent">
      <ul class="navbar-nav ml-auto text-center">
        
          
          
          
          
            <li class="nav-item">
              <a class="nav-link" href="/">
                <i class="iconfont icon-home-fill"></i>
                <span>首页</span>
              </a>
            </li>
          
        
          
          
          
          
            <li class="nav-item">
              <a class="nav-link" href="/archives/">
                <i class="iconfont icon-archive-fill"></i>
                <span>归档</span>
              </a>
            </li>
          
        
          
          
          
          
            <li class="nav-item">
              <a class="nav-link" href="/categories/">
                <i class="iconfont icon-category-fill"></i>
                <span>分类</span>
              </a>
            </li>
          
        
          
          
          
          
            <li class="nav-item">
              <a class="nav-link" href="/tags/">
                <i class="iconfont icon-tags-fill"></i>
                <span>标签</span>
              </a>
            </li>
          
        
          
          
          
          
            <li class="nav-item">
              <a class="nav-link" href="/about/">
                <i class="iconfont icon-user-fill"></i>
                <span>关于</span>
              </a>
            </li>
          
        
        
          <li class="nav-item" id="search-btn">
            <a class="nav-link" target="_self" href="javascript:;" data-toggle="modal" data-target="#modalSearch" aria-label="Search">
              <i class="iconfont icon-search"></i>
            </a>
          </li>
          
        
        
          <li class="nav-item" id="color-toggle-btn">
            <a class="nav-link" target="_self" href="javascript:;" aria-label="Color Toggle">
              <i class="iconfont icon-dark" id="color-toggle-icon"></i>
            </a>
          </li>
        
      </ul>
    </div>
  </div>
</nav>

  

<div id="banner" class="banner" parallax=true
     style="background: url('/img/default.png') no-repeat center center; background-size: cover;">
  <div class="full-bg-img">
    <div class="mask flex-center" style="background-color: rgba(0, 0, 0, 0.3)">
      <div class="banner-text text-center fade-in-up">
        <div class="h2">
          
            <span id="subtitle" data-typed-text="会场安排问题-贪心算法"></span>
          
        </div>

        
          
  <div class="mt-3">
    
    
      <span class="post-meta">
        <i class="iconfont icon-date-fill" aria-hidden="true"></i>
        <time datetime="2019-10-30 17:25" pubdate>
          2019年10月30日 下午
        </time>
      </span>
    
  </div>

  <div class="mt-1">
    
      <span class="post-meta mr-2">
        <i class="iconfont icon-chart"></i>
        
          2.4k 字
        
      </span>
    

    
      <span class="post-meta mr-2">
        <i class="iconfont icon-clock-fill"></i>
        
        
        
          20 分钟
        
      </span>
    

    
    
  </div>


        
      </div>

      
    </div>
  </div>
</div>

</div>

  </header>

  <main>
    
      

<div class="container-fluid nopadding-x">
  <div class="row nomargin-x">
    <div class="side-col d-none d-lg-block col-lg-2">
      

    </div>

    <div class="col-lg-8 nopadding-x-md">
      <div class="container nopadding-x-md" id="board-ctn">
        <div id="board">
          <article class="post-content mx-auto">
            <!-- SEO header -->
            <h1 style="display: none">会场安排问题-贪心算法</h1>
            
            
              <div class="markdown-body">
                
                <h1 id="问题描述"><a href="#问题描述" class="headerlink" title="问题描述"></a>问题描述</h1><p>假设要在足够多的会场里安排一批活动，并希望使用尽可能少的会场。设计一个有效的贪心算法进行安排。 对于给定的k个待安排的活动，计算使用最少会场的时间表。</p>
<span id="more"></span>
<p>Input<br>输入数据的第一行有1 个正整数k（k≤10000），表示有k个待安排的活动。接下来的k行中，每行有2个正整数，分别表示k个待安排的活动开始时间和结束时间。时间以0 点开始的分钟计。</p>
<p>Output<br>输出一个整数，表示最少会场数。</p>
<p>Sample Input</p>
<figure class="highlight basic"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><code class="hljs basic"><span class="hljs-number">5</span><br><span class="hljs-symbol">1 </span><span class="hljs-number">23</span><br><span class="hljs-symbol">12 </span><span class="hljs-number">28</span><br><span class="hljs-symbol">25 </span><span class="hljs-number">35</span><br><span class="hljs-symbol">27 </span><span class="hljs-number">80</span><br><span class="hljs-symbol">36 </span><span class="hljs-number">50</span><br></code></pre></td></tr></table></figure>
<p>Sample Output</p>
<figure class="highlight"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><code class="hljs">3<br></code></pre></td></tr></table></figure>
<h1 id="解题思路"><a href="#解题思路" class="headerlink" title="解题思路"></a>解题思路</h1><h2 id="证明问题满足贪心选择性质和最优子结构性质"><a href="#证明问题满足贪心选择性质和最优子结构性质" class="headerlink" title="证明问题满足贪心选择性质和最优子结构性质"></a>证明问题满足贪心选择性质和最优子结构性质</h2><p>1.<strong>贪心选择性质</strong>：因为活动安排问题每次安排活动时只需要考虑之前安排过的活动，不需要关心以后要安排的活动。因此该问题满足贪心选择性质。<br>2.<strong>最优子结构与性质</strong>：第n个活动安排时求的最优解一定是在第n-1个活动安排时求的最优解的基础之上的。因此该问题满足最优子结构与性质。</p>
<h2 id="贪心策略"><a href="#贪心策略" class="headerlink" title="贪心策略"></a>贪心策略</h2><p>1.定义一个结构体（或者类）用来保存需要安排活动的开始时间和结束时间。<br>2.按照开始时间的先后顺序进行排序， 开始时间早的排在前面。<br>3.定义一个整数数组（初始化为0，大小为会场个数），用于保存每个会场的结束时间<br>4.对于每一个活动遍历会场，直到找到一个会场结束时间小于此次活动开始的时间为止。</p>
<h1 id="代码"><a href="#代码" class="headerlink" title="代码"></a>代码</h1><h2 id="C"><a href="#C" class="headerlink" title="C++"></a>C++</h2><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br></pre></td><td class="code"><pre><code class="hljs cpp"><span class="hljs-meta">#<span class="hljs-meta-keyword">include</span> <span class="hljs-meta-string">&lt;iostream&gt;</span></span><br><span class="hljs-meta">#<span class="hljs-meta-keyword">include</span> <span class="hljs-meta-string">&lt;algorithm&gt;</span></span><br><br><span class="hljs-keyword">using</span> <span class="hljs-keyword">namespace</span> std;<br><span class="hljs-class"><span class="hljs-keyword">struct</span> <span class="hljs-title">huichang</span></span><br><span class="hljs-class">&#123;</span><br>	<span class="hljs-keyword">int</span> s;<br>	<span class="hljs-keyword">int</span> f;<br>&#125;;<br>huichang t[<span class="hljs-number">10000</span>+<span class="hljs-number">10</span>];<br><span class="hljs-keyword">int</span> n;<br><br><span class="hljs-function"><span class="hljs-keyword">bool</span> <span class="hljs-title">cmp</span><span class="hljs-params">(huichang a, huichang b)</span> </span>&#123;<br>	<span class="hljs-keyword">return</span> a.s &lt; b.s;<br>&#125;<br><span class="hljs-function"><span class="hljs-keyword">int</span> <span class="hljs-title">meeting</span><span class="hljs-params">()</span> </span>&#123;<br>	<span class="hljs-keyword">int</span> count_chang = <span class="hljs-number">0</span>;<br>	<span class="hljs-keyword">int</span> *a = <span class="hljs-keyword">new</span> <span class="hljs-keyword">int</span>[n + <span class="hljs-number">1</span>];	<span class="hljs-comment">//该数组于保存每个会场的结束时间</span><br>	<span class="hljs-keyword">for</span> (<span class="hljs-keyword">int</span> i = <span class="hljs-number">0</span>; i &lt; n+<span class="hljs-number">1</span>; i++) &#123;<br>		a[i] = <span class="hljs-number">0</span>;<br>	&#125;<br>	<span class="hljs-keyword">for</span> (<span class="hljs-keyword">int</span> i = <span class="hljs-number">1</span>; i &lt;= n; i++) &#123;<br>		<span class="hljs-keyword">for</span> (<span class="hljs-keyword">int</span> j = <span class="hljs-number">1</span>; j &lt;= n; j++) &#123;<br>			<span class="hljs-keyword">if</span> (a[j] &lt;= t[i].s) &#123;<br>				a[j] = t[i].f;<br>				<span class="hljs-keyword">if</span> (j &gt;= count_chang + <span class="hljs-number">1</span>)	<span class="hljs-comment">//记录已使用了的会场个数</span><br>					count_chang++;<br>				<span class="hljs-keyword">break</span>;<br>			&#125;<br>		&#125;<br>	&#125;<br>	<span class="hljs-keyword">delete</span>[]a;<br>	<span class="hljs-keyword">return</span> count_chang;<br>&#125;<br><span class="hljs-function"><span class="hljs-keyword">int</span> <span class="hljs-title">main</span><span class="hljs-params">()</span> </span>&#123;<br>	<br>	cin &gt;&gt; n;<br>	<span class="hljs-keyword">for</span> (<span class="hljs-keyword">int</span> i = <span class="hljs-number">1</span>; i &lt;= n; i++) &#123;<br>		cin &gt;&gt; t[i].s &gt;&gt; t[i].f;<br>	&#125;<br>	<span class="hljs-built_in">sort</span>(t+<span class="hljs-number">1</span>,t+n+<span class="hljs-number">1</span>,cmp);<br>	cout &lt;&lt; <span class="hljs-built_in">meeting</span>() &lt;&lt; endl;<br>	<span class="hljs-keyword">return</span> <span class="hljs-number">0</span>;<br>&#125;<br><br></code></pre></td></tr></table></figure>
<h2 id="JAVA"><a href="#JAVA" class="headerlink" title="JAVA"></a>JAVA</h2><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br><span class="line">47</span><br><span class="line">48</span><br><span class="line">49</span><br><span class="line">50</span><br><span class="line">51</span><br><span class="line">52</span><br><span class="line">53</span><br><span class="line">54</span><br></pre></td><td class="code"><pre><code class="hljs java"><span class="hljs-keyword">import</span> java.util.Scanner;<br><span class="hljs-keyword">import</span> java.util.Arrays;<br><span class="hljs-keyword">import</span> java.util.Comparator;<br><span class="hljs-keyword">public</span> <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">Main</span> </span>&#123;<br> <br>    <span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> <span class="hljs-title">main</span><span class="hljs-params">(String[] args)</span> </span>&#123;<br>        <span class="hljs-comment">// TODO Auto-generated method stub</span><br>        Scanner sc = <span class="hljs-keyword">new</span> Scanner(System.in);<br> <br>            <span class="hljs-keyword">int</span> n = sc.nextInt();<br>            HuiChang []t = <span class="hljs-keyword">new</span> HuiChang[n+<span class="hljs-number">1</span>];<br>            <span class="hljs-keyword">for</span>(<span class="hljs-keyword">int</span> i=<span class="hljs-number">1</span>;i&lt;=n;i++)<br>                t[i] = <span class="hljs-keyword">new</span> HuiChang();<br>             <br>            <span class="hljs-keyword">for</span>(<span class="hljs-keyword">int</span> i = <span class="hljs-number">1</span>;i&lt;=n;i++)&#123;<br>                t[i].s = sc.nextInt();<br>                t[i].f = sc.nextInt();<br>            &#125;<br>            MyComparator cmp = <span class="hljs-keyword">new</span> MyComparator();<br>            Arrays.sort(t,<span class="hljs-number">1</span>,n+<span class="hljs-number">1</span>,cmp);<br>            System.out.println(meeting(t));<br>    &#125;<br>    <span class="hljs-function"><span class="hljs-keyword">private</span> <span class="hljs-keyword">static</span> <span class="hljs-keyword">int</span> <span class="hljs-title">meeting</span><span class="hljs-params">(HuiChang []t)</span></span>&#123;<br>        <span class="hljs-keyword">int</span> count_chang = <span class="hljs-number">0</span>;<br>        <span class="hljs-keyword">int</span> n = t.length-<span class="hljs-number">1</span>;<br>        <span class="hljs-keyword">int</span> []a = <span class="hljs-keyword">new</span> <span class="hljs-keyword">int</span> [n+<span class="hljs-number">1</span>];<br>        <span class="hljs-keyword">for</span>(<span class="hljs-keyword">int</span> i=<span class="hljs-number">0</span>;i&lt;a.length;i++) &#123;<br>            a[i] = <span class="hljs-number">0</span>;<br>        &#125;<br>        <span class="hljs-keyword">for</span>(<span class="hljs-keyword">int</span> i=<span class="hljs-number">1</span>;i&lt;=n;i++) &#123;<br>            <span class="hljs-keyword">for</span>(<span class="hljs-keyword">int</span> j=<span class="hljs-number">1</span>;j&lt;=n;j++) &#123;<br>                <span class="hljs-keyword">if</span>(a[j]&lt;=t[i].s) &#123;<br>                    a[j] = t[i].f;<br>                    <span class="hljs-keyword">if</span>(j&gt;=count_chang+<span class="hljs-number">1</span>)<br>                        count_chang++;<br>                     <br>                    <span class="hljs-keyword">break</span>;<br>                &#125;<br>            &#125;<br>        &#125;<br>        <span class="hljs-keyword">return</span> count_chang;<br>    &#125;<br>&#125;<br><span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">HuiChang</span> </span>&#123;<br>    <span class="hljs-keyword">public</span> <span class="hljs-keyword">int</span> s;<br>    <span class="hljs-keyword">public</span> <span class="hljs-keyword">int</span> f;<br>&#125;<br><span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">MyComparator</span> <span class="hljs-keyword">implements</span> <span class="hljs-title">Comparator</span>&lt;<span class="hljs-title">HuiChang</span>&gt;</span>&#123;<br>    <span class="hljs-meta">@Override</span><br>    <span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">int</span> <span class="hljs-title">compare</span><span class="hljs-params">(HuiChang o1, HuiChang o2)</span> </span>&#123;<br>        <span class="hljs-keyword">if</span>(o1.s &gt; o2.s) <span class="hljs-keyword">return</span> <span class="hljs-number">1</span>;<br>        <span class="hljs-keyword">else</span> <span class="hljs-keyword">return</span> -<span class="hljs-number">1</span>;<br>    &#125;<br>&#125;<br></code></pre></td></tr></table></figure>

                
              </div>
            
            <hr/>
            <div>
              <div class="post-metas my-3">
  
    <div class="post-meta mr-3 d-flex align-items-center">
      <i class="iconfont icon-category"></i>
      

<span class="category-chains">
  
  
    
      <span class="category-chain">
        
  <a href="/categories/%E7%AE%97%E6%B3%95%E4%B8%8D%E8%83%BD%E4%B8%A2/" class="category-chain-item">算法不能丢</a>
  
  

      </span>
    
  
</span>

    </div>
  
  
    <div class="post-meta">
      <i class="iconfont icon-tags"></i>
      
        <a href="/tags/C/">#C++</a>
      
        <a href="/tags/%E7%AE%97%E6%B3%95%E4%B8%8D%E8%83%BD%E4%B8%A2/">#算法不能丢</a>
      
        <a href="/tags/Java/">#Java</a>
      
    </div>
  
</div>


              
  

  <div class="license-box my-3">
    <div class="license-title">
      <div>会场安排问题-贪心算法</div>
      <div>https://bolg.plumdong.top/2019/10/30/会场安排问题-贪心算法/</div>
    </div>
    <div class="license-meta">
      
        <div class="license-meta-item">
          <div>作者</div>
          <div>马振东</div>
        </div>
      
      
        <div class="license-meta-item license-meta-date">
          <div>发布于</div>
          <div>2019年10月30日</div>
        </div>
      
      
      
        <div class="license-meta-item">
          <div>许可协议</div>
          <div>
            
              
              
                <a target="_blank" href="https://creativecommons.org/licenses/by/4.0/">
                  <span class="hint--top hint--rounded" aria-label="BY - 署名">
                    <i class="iconfont icon-by"></i>
                  </span>
                </a>
              
            
          </div>
        </div>
      
    </div>
    <div class="license-icon iconfont"></div>
  </div>



              
                <div class="post-prevnext my-3">
                  <article class="post-prev col-6">
                    
                    
                      <a href="/2019/10/30/%E4%B8%8D%E5%8F%AF%E5%8F%98%E6%80%A7%E7%9A%84%E4%BC%98%E7%82%B9%EF%BC%88%E4%BB%A5String%E4%B8%BA%E4%BE%8B%EF%BC%89/" title="不可变性的优点（以String为例）">
                        <i class="iconfont icon-arrowleft"></i>
                        <span class="hidden-mobile">不可变性的优点（以String为例）</span>
                        <span class="visible-mobile">上一篇</span>
                      </a>
                    
                  </article>
                  <article class="post-next col-6">
                    
                    
                  </article>
                </div>
              
            </div>

            
          </article>
        </div>
      </div>
    </div>

    <div class="side-col d-none d-lg-block col-lg-2">
      
  <aside class="sidebar" style="margin-left: -1rem">
    <div id="toc">
  <p class="toc-header">
    <i class="iconfont icon-list"></i>
    <span>目录</span>
  </p>
  <div class="toc-body" id="toc-body"></div>
</div>



  </aside>


    </div>
  </div>
</div>





  



  



  



  



  







    

    
      <a id="scroll-top-button" aria-label="TOP" href="#" role="button">
        <i class="iconfont icon-arrowup" aria-hidden="true"></i>
      </a>
    

    
      <div class="modal fade" id="modalSearch" tabindex="-1" role="dialog" aria-labelledby="ModalLabel"
     aria-hidden="true">
  <div class="modal-dialog modal-dialog-scrollable modal-lg" role="document">
    <div class="modal-content">
      <div class="modal-header text-center">
        <h4 class="modal-title w-100 font-weight-bold">搜索</h4>
        <button type="button" id="local-search-close" class="close" data-dismiss="modal" aria-label="Close">
          <span aria-hidden="true">&times;</span>
        </button>
      </div>
      <div class="modal-body mx-3">
        <div class="md-form mb-5">
          <input type="text" id="local-search-input" class="form-control validate">
          <label data-error="x" data-success="v" for="local-search-input">关键词</label>
        </div>
        <div class="list-group" id="local-search-result"></div>
      </div>
    </div>
  </div>
</div>

    

    
  </main>

  <footer>
    <div class="footer-inner">
  
    <div class="footer-content">
       <a href="https://hexo.io" target="_blank" rel="nofollow noopener"><span>Hexo</span></a> <i class="iconfont icon-love"></i> <a href="https://github.com/fluid-dev/hexo-theme-fluid" target="_blank" rel="nofollow noopener"><span>Fluid</span></a> 
    </div>
  
  
  
  
</div>

  </footer>

  <!-- Scripts -->
  
  <script  src="https://lib.baomitu.com/nprogress/0.2.0/nprogress.min.js" ></script>
  <link  rel="stylesheet" href="https://lib.baomitu.com/nprogress/0.2.0/nprogress.min.css" />

  <script>
    NProgress.configure({"showSpinner":false,"trickleSpeed":100})
    NProgress.start()
    window.addEventListener('load', function() {
      NProgress.done();
    })
  </script>


<script  src="https://lib.baomitu.com/jquery/3.6.0/jquery.min.js" ></script>
<script  src="https://lib.baomitu.com/twitter-bootstrap/4.6.1/js/bootstrap.min.js" ></script>
<script  src="/js/events.js" ></script>
<script  src="/js/plugins.js" ></script>


  <script  src="https://lib.baomitu.com/typed.js/2.0.12/typed.min.js" ></script>
  <script>
    (function (window, document) {
      var typing = Fluid.plugins.typing;
      var subtitle = document.getElementById('subtitle');
      if (!subtitle || !typing) {
        return;
      }
      var text = subtitle.getAttribute('data-typed-text');
      
        typing(text);
      
    })(window, document);
  </script>




  
    <script  src="/js/img-lazyload.js" ></script>
  




  
<script>
  Fluid.utils.createScript('https://lib.baomitu.com/tocbot/4.18.2/tocbot.min.js', function() {
    var toc = jQuery('#toc');
    if (toc.length === 0 || !window.tocbot) { return; }
    var boardCtn = jQuery('#board-ctn');
    var boardTop = boardCtn.offset().top;

    window.tocbot.init(Object.assign({
      tocSelector     : '#toc-body',
      contentSelector : '.markdown-body',
      linkClass       : 'tocbot-link',
      activeLinkClass : 'tocbot-active-link',
      listClass       : 'tocbot-list',
      isCollapsedClass: 'tocbot-is-collapsed',
      collapsibleClass: 'tocbot-is-collapsible',
      scrollSmooth    : true,
      includeTitleTags: true,
      headingsOffset  : -boardTop,
    }, CONFIG.toc));
    if (toc.find('.toc-list-item').length > 0) {
      toc.css('visibility', 'visible');
    }

    Fluid.events.registerRefreshCallback(function() {
      if ('tocbot' in window) {
        tocbot.refresh();
        var toc = jQuery('#toc');
        if (toc.length === 0 || !tocbot) {
          return;
        }
        if (toc.find('.toc-list-item').length > 0) {
          toc.css('visibility', 'visible');
        }
      }
    });
  });
</script>


  <script src=https://lib.baomitu.com/clipboard.js/2.0.11/clipboard.min.js></script>

  <script>Fluid.plugins.codeWidget();</script>


  
<script>
  Fluid.utils.createScript('https://lib.baomitu.com/anchor-js/4.3.1/anchor.min.js', function() {
    window.anchors.options = {
      placement: CONFIG.anchorjs.placement,
      visible  : CONFIG.anchorjs.visible
    };
    if (CONFIG.anchorjs.icon) {
      window.anchors.options.icon = CONFIG.anchorjs.icon;
    }
    var el = (CONFIG.anchorjs.element || 'h1,h2,h3,h4,h5,h6').split(',');
    var res = [];
    for (var item of el) {
      res.push('.markdown-body > ' + item.trim());
    }
    if (CONFIG.anchorjs.placement === 'left') {
      window.anchors.options.class = 'anchorjs-link-left';
    }
    window.anchors.add(res.join(', '));

    Fluid.events.registerRefreshCallback(function() {
      if ('anchors' in window) {
        anchors.removeAll();
        var el = (CONFIG.anchorjs.element || 'h1,h2,h3,h4,h5,h6').split(',');
        var res = [];
        for (var item of el) {
          res.push('.markdown-body > ' + item.trim());
        }
        if (CONFIG.anchorjs.placement === 'left') {
          anchors.options.class = 'anchorjs-link-left';
        }
        anchors.add(res.join(', '));
      }
    });
  });
</script>


  
<script>
  Fluid.utils.createScript('https://lib.baomitu.com/fancybox/3.5.7/jquery.fancybox.min.js', function() {
    Fluid.plugins.fancyBox();
  });
</script>


  <script>Fluid.plugins.imageCaption();</script>

  <script  src="/js/local-search.js" ></script>





<!-- 主题的启动项，将它保持在最底部 -->
<!-- the boot of the theme, keep it at the bottom -->
<script  src="/js/boot.js" ></script>


  

  <noscript>
    <div class="noscript-warning">博客在允许 JavaScript 运行的环境下浏览效果更佳</div>
  </noscript>
</body>
</html>
